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The WikiReader contains the following major hardware components

Power supply converter

  • Input Range 2.1 to 3.4 volts
  • Power source 2 * AAA batteries
  • Short press (< 1s) power button for ON
  • Long press (> 2s) power button for OFF
  • GPIO monitor of power switch
  • GPIO controlled shutdown

Processor

  • Single chip Epson S1C33E07 Micro controller
  • Internal RAM areas (8kB, 2kB)
  • LCD controller with frame buffer
  • S1C33 family RISC core
  • SPI interface
  • Serial interfaces
  • GPIO interfaces
  • Keypad interface (change of state detector)
  • ADC inputs and PWM output

SDRAM

  • up to 32MB supported
  • Bus width 16 bit
  • 4 bank device

Boot ROM

  • SPI 64kB FLASH
  • In-circuit reprogrammable
  • Connected to MCU SPI interface
  • MCU configured to boot from SPI
  • Re-flash ROM (WARNING only use if advised to)

LCD Display Module

  • Monochrome LCD module
  • Resolution: 240 * 208 pixels
  • Level converters on LCD module
  • 4 bit interface to MCU LCD controller

Touch screen

  • Capacitive Touch Panel
  • Data sent via asynchronous serial protocol
  • GPIO touch down indication

MicroSD card socket

  • Supports SD and SDHC cards (512MB, 2GB, 4GB, 8GB) 16GB and above see: SD Cards for more details
  • Buffered connection to MCU SPI interface
  • Power controlled by MCU GPIO
  • A quick way to check a card is usable to copy the calc.elf file from the previous card the new one, then hold the History Key and power on. If the calculator shows the card is usable. (no need to erase the card for this check)

Three function keys

  • Connected to MCU keypad interface

Analog I/O

  • Battery voltage (ADC in)
  • LCD voltage (ADC in)
  • Thermistor (ADC in)
  • Contrast control (PWM out)

Debug connector

  • 8 pads under a seal in the battery compartment
  • The test jig connects to these using spring loaded test probes
  • starting from the row nearest the batteries, left (near SD Card) to right the signals are:
Row signal signal signal signal
1st row [BAT-] [PROG] [VSS] [RXD]
2nd row [BAT+] [3.3V] [RESET] [TXD]
  • PROG, RESET, RXD, TXD are all 3.3V signals referenced to VSS
  • RESET -> VSS for power on reset
  • PROG -> VSS and use flash07 to reprogram FLASH ROM
  • BATT+/- for external 3 volt power supply
  • 3.3V is the internal regulated power rail, it could power a 3.3V RS232 converter chip
  • Do not inject power into the 3.3V Pin, it is output only
  • RXD/TXD are set to 19200 8N1 by mbr
  • BAT- is not the same as VSS
  • Test pin spacing: 2mm centre to centre
  • Opening in case is 4.3 mm x 8.3 mm

Dimensions

  • Width: 100 mm
  • Height: 100 mm
  • Depth: 20 mm
  • Weight: 120g

Board, inside the Wikireader

WikiReader PCB

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